The present invention relates to an improvement to a numerically controlled machine for curving, forming, folding or bending bars or sections, and to methods for controlling such a machine.
Current machines of this type have various limitations. For example, the loops are difficult to produce, particularly when their diameter is very large and they need to be closed. The number of radii possible on one and the same part is often limited. It is rarely possible to form loops at both ends of a part. Producing folds at the final end of a long part entails slowing of the folding as a result of the high inertia of the part. The flatness of closed frames is difficult to guarantee because of the twisting of the part on the initial wire. Parts having both large radii with a large wrap angle and small radii followed by short straight lengths pose problems of variation in folding or pin/folding snout distance. Producing reverse folds (bayonets) takes time because of changes in the sides of the folding pin. Soft or coated wires are difficult to work because of constraints on contact and relative movement between the tool and the wire.
These functions, which were difficult or even impossible to achieve beforehand, are achieved by providing a bending machine with a snout which is retractable.
This is achieved with a numerically controlled machine for curving, forming, folding or bending a bar, having conventional components including a bed and a rotary bending head. The rotary bending head is able to obtain folds in various planes. A bar is moved horizontally along a line of travel by a feed station, arranged upstream, and is conveyed through a folding snout carried by the bed, and then through a turner of the bending head. The turner is formed of a bending roller and a folding pin, and is able to turn in a horizontal plane about an axis of rotation aligned with the axis of the bending roller.
In accordance with the present invention, the folding snout is mounted to move in translation along the line of travel, and is moved continuously between one or more forward bending positions in which the snout is near the roller, and one or more positions which are retracted toward the upstream end, and the bending region between the turner and the bed is left totally free.
The invention will be better understood from the detailed description which is provided below, with reference to the following illustrations.